Lawn trimming device



Feb.- l6, 1940. w scoFlELD 2,188,961

LAWN TRIMMING DEVICE INVENTOR ATTORNEY Feb' 6, 1940- l.. w. scoFlELD 2,188,961

LAWN TRIMMING DEVI CE /55l /56 /47 ATTORNEY Feb- 6 1940. L. w. scoFlELD 2,188,961

LAWN TRIMMING DEVICE Filed Aug. 20, 1957 5 Sheets-Sheet 5 @Il F5712 lNvENTOR /45 EST/5e W Scar/ELUv lil Patented Feb. 6, 1940 TRIBIMING DEVICE Lester W. Scofield, Pound Ridge, N. Y., assignor to Frank Cataldo, Trinity Pass, New Canaan,

Conn.

Application August 20,

11 Claims.

' This invention relates to lawn trimmers.

Itis anl object of the present invention to provitle a lawn trimmer in which the cutter unit is of thewreciprocating type and which is particui larly adapted to trim the edges of lawns, as ad.

pacent to walks, gardens and buildings where the conventional rotatory mower `supported between two ground wheels cannot be used.

Itis an object ofthe invention to provide a lawn trimmer in which the` cutter unit may be selectively supported to cut in a vertical and a horizontal plane. l i

Accordingly, va feature of the invention resides in providing a lawn trimmer in which the cutter unit comprises a iixed cutter having a series of cutting teeth and a cooperating movable cutter having a series of cutting teeth, in which the cutting unit is supported to extend downwardly at one side of the carrying frame and in which the movable cutter is reciprocated longitudinally of the fixed cutter by a connection with the ground wheel.

Another feature of the invention resides in 'providing a lawn trimmer in which the cutter unit comprises a fixed cutter having a series of cutting teeth and a cooperating movable cutter having a series of cutting teeth, in which the movable cutter is reciprocated longitudinally of the iixed cutter by a connection with the ground -Wheel and in which the cutter unit may be selectively supported on the frame in vertical and horizontal positions.

-Another feature of the `invention resides in providing a lawn trimmer in which an arcuate guide is provided on the supporting frame, in which the cutter unit'is movable with a carrier block on said guide to belocated in divers positions relative to the'frame and in which a gear is provided coaxial with the ground wheel and rotatable therewith to cooperate with a gear o said carrier to a'ctuate said cutter unit.

Yet another feature of the invention resides in providing a lawn trimmer in which the gear driving means for the cutter unit is enclosed in an open sided housing of the ground Wheel.

Another feature of the invention consists in' providing a lawn trimmer provided with a means for supporting and operating the cutter unit at both sidesof the ground wheel.

Other objects and features willhereinafter appear. y i l.

In the drawings: l

Figure 'l is a side Jview of rone form of the lawn trimmer.

Fig.' 2-is a view taken onthe line 2--2 of l.

1937, Serial No. 160,023

T OFFICE Fig. 2a is a fragmentary view, similar toy 2, but showing the cutter unit in a horizontal po- Y sition.

Fig. 3 is a detail View showing the `mannerin which the cutter unit is associated with the frame;

Fig. 4 is a detail View showing mounting for the cutter unit.

Fig. 5 is a side View ofa modiedform'nof the.

invention.

Fig. 6l is a sectional view of the form shown in Fig. 5. v 1 Fig. '7 is a fragmentarydetail view showing a modified the relation of the frame carrier block and'cutl ter unit when in the vposition rin Fig. 5.

Fig. 8 is a fragmentary View similar to Fig. 6 n

showing the cutter unit adjusted -in a horizontal position.

.Fig` 9 is a fragmentary detail view similar Ato Fig. 7, but showing therelation of the frame carrier block and cutter unit when in the position shown in Fig. 8.

Fig. 10 is an exploded detail View showing a construction of the carrier block and its relationship with the frame and cutter unit 'when the of parts shown in the accompanying drawings,

which are merely illustrativeof the present preferred embodiments, since the invention isl capable of other embodiments, and the phraseology employed is for the purpose of description and not of limitation.

Referring more particularly to the drawings and iirst to Figs. 1 through 3 and Fig. 11, there is disclosed a lawn trimming device having a ground Wheel 2l, preferably formed with a rim 22 connected to a central hub'portion 23 by a '4" web 24. A Irubber tire 25 with serrations 26 in the outer face thereof may, as shown, be adfvantageously mounted on the rim to improve traction. l

Positioned at opposite sides of the ground wheel 2| is a main yoke frame member 2l whichrec'eives the main axle 28 to thus rotatably mount the ground wheel. Preferably a roller bearing 29 is rincorporated. in the hub portion 23 and maintained in position by the web 24 'which is secured to flanges 30 on the hub portion by screws 3|.

As shown the yoke member 2l is provided with a pair of arms 32 land 33 which extend upwardly to be suitably connected to opposite sides of a conventional handle 34. The yoke frame 27 includes also a horizontal U-shaped supporting extending arm 38 provides means for selectivelyv supporting a cutter unit 46 in a vertical and horizontal position respectively, see especially Fig. 2, whereby the same may be used to trim not only the' edge of a lawn but also to flat trim the lawn adjacent the edge.

The cutter unit 46 which may thus be selectivelysupported in horizontal and vertical positions comprises a xed cutter 4| having a series of V-shaped cutting teeth 42 and a cooperating movab-le cutter 43 having a series of V-shaped cutting teeth 44 and mounted for reciprocatory movement longitudinally of the xed cutter. Screws 45 on the fixed cutter and extending into slots 46 in the movable cutter serve to guide the latter. during its reciprocatory movement. A spring plate 4l resting adjacent one edge of a longitudinal rib 48 on the xed cutter and maintained in yielding engagementwith the movable cuttery by the screws 45, provides an emcient means for achieving a proper shearing relationship betweenthe cutting teeth 42 and 44 of the respective cutters. l

For operativelyassociating the cutter unit with the U-shaped section 35 and the ground wheel 2| to accomplisha vertical cut there is mounted on the'inner sideof one of the arms 36a pinion gear 49 having a flange 56 and an integral stepped shaft 5| extending through the arm 36. j As shown, a sleeve member '52 is inserted on the stepped shaft and secured thereto for rotation therewith by a key 53 in the shaft 5| which enters a keyway 54 in an outwardly projecting portion 55 of the sleeve 52. It is to be especially noted that the portion 55 of the sleeve is eccentric with respect to the shaft 5|.

A flange portion 56 of the sleeve 52 and the flange portion 56 of the pinion gear 46, respectively overlying opposite sides of a ball bearing 51 suitably fixed to the arm 36 provides means for maintaining the keyed together shaft 5| and sleeve 52 in association with the U-shaped section.

As shown most clearly in Figs. lV and 3, the fixed cutter 4| of the cutter unit 46 is provided at one end with a connecting plate 58 encircling the flange 56 of the sleeve 52 and fixed to the supporting frame arm 36 as by screws 55. To complete the mounting of the cutter unit the movable cutter 43 has connected adjacent one end by means of a pivot stud 66, a link 6I hav-` ing a hub or bearing portion 62 mounted on the eccentric portion 55 of the sleeve 52. Ak bearing collar 63 on the shaft 5| and held thereon and against the hub portion 62 of the linkl 6|l by a nut 64 in screw threaded relation with the shaft 5|, serves to effectively maintain the shaft 5|, eccentric 55 and movable cutter 43 in operative relation.

.With this mounting and construction, as the eccentric 55 is rotated the movable cutter is caused to reciprocate and the teeth 42 and 44 on the cooperating cutters engage in shearing relation to trim the grass and the like that projects or hangs over the lawn edge. l

To accomplish this actuation of the cutter unit in a most simple and eiective manner there is coaxially associated with the ground wheel by means of brackets 65 suitably secured to and extending from one side of the web 24,` amain gear 66 having teeth 61 engageable directly with teeth 6B on the pinion gear 49. Thus when the ground wheel 2| is moved over vthe lawn,'as by the conventional handle 34, the main gearv66 is rotated therewith to concurrently rotate the pinion gear 46 and associated eccentric 55 to reciprocate the movable cutter 43.

When it is desired to support the cutter unit 46 2 y to achieve a 4horizontal cut it is merely necessary to remove the screwsr 53, bearing collar. 63 and nut 64, whereupon the cutter unit 46 may be pulled off of the sleeve 52.

the cutter unit 46 associated with the horizontal The collar 63 and y nut 64 may then be replaced on the shaft 5|gand j 25 flange 36 on the downwardly extending-arm 36 of the yoke frame 2l. y l

As in the case of the side arm 3 6 of. the -U.-

shaped section 35 there isfrnounted on the upper side of the horizontal flange 39 a pinion gear 69 having a hub i6 engageable with a ball bearing" 1| suitably fixed on the flange, andhaving-a preferably integral shaft-'l2 extending through the bearing. A sleeve ,'53 having an eccentric portion 'I4 projecting downwardly fromthevsupporting ange arm 36, and having aflange por-f tion 'l5 engageable with theouter sidel 'of vthe flange arm 39 'is keyed to the lshaft ,'lZfor rotation therewith. With this construction, the cutter unit v,46 may readily be supported in a horizontal position by merely securing the connecting' plate 58' of the fixed cutter 4| to the supporting flange 36 by thescrews 5S and by inserting the hub 62 ofthe link 6| on thek eccentric 14, whereupon a collar 'I6 and nut l1, similar to the collar 63 and nut-64 heretofore described, maylikewisebe inserted on the shaft 'I2 to maintain'the movable cutter 43 andeccentric, 74 inoperative association.

Preferably, and as shown most'clearly in-Fig. l, a section 78 of the rim 22 and a section'l of the tire 25 are made separable to ,facilitate the association and disassociationof the cutter unit 40 with the horizontal supporting flange 36. Cooperating shoulders 86 and 8| on the'separable section 'E8 and main portion of the rim 2210espectively and adapted to receive screws 62 p-rcvide an advantageousv means forfsecuring the separable section '|8 in position. f

Forrotating the pinion 69, which as shownis upon movement of the groundk wheel overthe lawn, be reciprocated .to cooperate with the fixed cutter to achieve a horizontal cut. e y y' It is to be noted that both of the main gears 66 and 84 and both the pinions49 and SSl'are at all times operatively associated with the-ground wheel 2| Vand that the change-over from-'a ver- 60 abevel gear, to cause actuation of the movable tical to a horizontal support ofthe .cutter unit is a most simple' operation. It is to be further noted that the rim 22 yof the ground wheel 2| provides'an open sided housing'89 .for enclosing the driving gears for the cutter unit, thus making for a more compact device and one in which thegears are protected from stones, pebblesand the like which may be thrown upwardlyby the cutter unit during the operation thereof.

If desired, in order that the cutter unit may l be adjusted upwardly and downwardly when vertically supported, and inwardly and outwardly when horizontally supported, a modified cutter unit 40a, as shown in Fig. 4, may be utilized. This modified unit 40a is similar tothe unit rst described. In it, however, the connecting plate 58aof the fixed cutter 4|a is formed with a pair of longitudinal slots 86therein adapted to receive the connecting screws 59 and permit longitudinal adjustment of the cutter relative to .theside arm 36 or horizontal flange 39 as the case may be. Also, in the modified unit the actuating link Gla ofthe movable cutter 43a is provided ywith a series 81 of holes 88. Thus when the lfixed. cutter is longitudinally adjusted through the pair of slots the movable-cutter may be similarlyiadjusted by inserting the eccentric 55 or 14, as the case mayv be, in a proper one offthe holes 88 in vthe link.

The main yoke frame 21 may alsobe used to' support auxiliary devices such as the weedA cutter 90, roller 9| and cultivator or marker 92 of Figs. 13,14 and 12 respectively, through the provision vof a connecting plate 31- on 'the U-s'ection 35 adapted to receive and support plates 93 of the auxiliary devices, and tohold the latter-thereon as by screws 94 in holes 95 and 96 in the connect- .ing plate 31 and the plates 93 respectively.

' Instead of the form disclosed in Figs. 1 throughv Lland Fig. 11, a lawn trimmer 91 ofthe modified form disclosed in Figs.v 5 through 9 may be utilized. Like the form first described this modified lawn trimmer includes a cutter unit 98 adapted to be vertically supported at one. side of a ground Wheel 99 to trim the projecting or overhanging grass at the lawn edge and to be also supported horizontally toeffectively trim the 'lawn adjacent the lawn edge.

greater range in unit. s, As shown clearly in Figs. 5 and 6 a` conventhe adjustment ofthe cutter tional handle is provided to which .are se--` cured at opposite sides thereof by bolts |0| ,and

nuts |02 a pair of upwardly extendingv arms |03 and |04 of a main yoke frame member .|05 on whichis rotatably mounted by means of an axle |06 the ground wheel 99. j.

This ground wheel includes a rim |01 on which is preferably mounted a serrated rubber tire |08 and which on its inner face has formed an internal main frame is formed with arcuate portions ||4 at either sidethereof integrallyconnected to the arms |03 and |04 and to radial arms H5, I6 and ||1 extending from the ycentral axle carrying portions ||8 of the main yoke frame.

A s; shown, the rearwardly extending radial armsy ||5 are joined by a connecting portion 9 to provide a U-shaped strengthening section for the With the modified form, "however, it is possible to achieve a somewhat erves to rotatably mount yoke frame and. to support auxiliary devices, such as shown in Figs. r12, 13 and 14. f

The cutter .unit 98 is generally similar to the unit 40 .first described and includes a fixed cutter and a'movable cutter |2| mounted `for reciprocatory movement longitudinally thereof. Preferably, however, and as shown the fixed cutter is formed'with opposed sets |22 and |23 of V- shaped cutting teeth |24 adapted to respectively cooperate with opposed sets |25 and |26 ofr cutting teeth |21 formed onl the movable cutter |2|.

As in the case of the cutter unit 40,*screws |28 on ther fixedr cutter |20 extending into longitudinal slots |29'in `the movable cutter |2| serve to guide the latter during its reciprocatory movement, while a spring plate |30 overlying the movable cutter and maintained in engagementv therewith by' the screws |28 pro-vides an, advantageous 'means'forinsuring a proper shearing relationship` between the cutting teeth |24 and. |21.of the lrespective cutters.

Now of` particular importance it is to be noted that for enabling the support of the cutterunit in divers positions there are formed in the arcuate portions' H4 arcuatev guide slots |3|, either of which is adapted to receive guide lugs |32 and placed on lthe other side of the ground iwheel so that the other.4 pair of cooperating sets of cutter teeth may be brought into operative position,

As shown mosty clearly in Fig. 10 the carrier block |34 includes a plate section |35, on which the lugs |32 and.|33 are formed, adapted to overvlie the outer face on one of the arcuate'portions |4 'depending-on which side of the ground wheel it is desired'to support the cutter unit. .This plate section'y is formed with a central bore |36 in which is suitably secured a ball bearing 31 adapted to receive astub shaft |38 at the outer .end of which andpreferably integral. therewith is an actuating member |39v for the imovable cutterv |2|. A U- shaped section |40 is also formed on the block extending at a right angle to the plate section |35. A lug |4| at the rear of the U-shaped section |40 is engageable with the 'arcuate portions I4 and n cooperates with the lugs |32 and |33 in guiding and supporting the carrierblock |34 as the latter is moved to divers adjusted positions. i

: Mounted on the stub shaft |38 to engage the internalgear |09 4and thus rotate the cutter actuating member 39 isa` pinion gear |42. Any suitablemeans such as the screw |43 in the hub |44 ofthe `pinion |42 may be utilized to insure concurrent rotation of' the shaft |38.

For yassociating the cutter unit 98 with the carrier block |34 the fixed cutter 20 is formed pinion |42 `and stub y at one end with a'connecting plate |45 having' a central opening r|46 therein,` witha bolt hole |41 at one side andan arcuate bolt receiving slot |48 l at the other'side thereof.

vFor associating the movable cutter 2| with the actuating member |39 'a link |49 is connected at lonelend byka pivot pin '|50 to the movable cutter 2| and formed at the other-end witha hub bearing portion 15| adapted to receive a stub shaft |52. As shown most clearly in'Fig. 7, this shaft |52 extendsfrom either side of the link bearing |f5| and has mounted at one end a roller collar |53 and at the other end a roller collar |54 respectively held on the shaft by screws |55 and |56 to cooperate with the actuating member'l33 in a manner which will presently bedescribed in detail. A bushing `|51 may be advantageously fitted in the link bearing |5| to receive the stub shaft |52. Longitudinal movement of the stub shaft is arrested by the screw held roller collars |53 and |54 while an additional bearing surface is provided by a circumferential flange |58 von the shaft between the -bearing |5| and collar |53;

' With this construction when it is desired'to associate the cutter unit 96 with the carrier block |34 to accomplish -a vertical out as shown in Fig. 5, a U-shaped spacer block |59 is placed on the outer face of the plate section |35, the connecting plate |45 of the fixed cutter |20 is placed on the U-shaped spacer block so that the opening |45 therein receives the actuating member |39,.which is of cylindrical shape. Bolts Hill are then inserted through one of the arcuate guide slots |3| fn the main yoke frame |05to pass through holes itl in the plate section |35 and thence through suitable holes lin the spacer block |59 -to eX- tend through the hole |41 and slot |48y respectively'in thefixed cutter connecting plate |45. Nuts v|53 on the bolts |60 function to lock the fixed cutter |26 in position and with the bolts |68 to fix to thek carrier block |34 to the arcuate portions ||4 of the main frame |65.

Concurrently with the positioning of thec'onnecting plate |45 of the fixed lcutter |20, the roller collar |53 on the link stud lshalt |52 is inserted in an eccentric cam' groove |64 'formed in the iace of the actuatingv 'cylinder |39. A channel bracket fixed tothe connecting plate` |45, as by screws |55, and overlying the link |49 serves to maintain the collar |53 in the cam groove |64.

`With this construction, upon movement of the ground wheel 99, as by the handle lll, theA internal geai1 |55 engages the pinion |42 to rotate the latter and through the cooperation of the eccentric cam groove |54 and the collar |53 to reciprocate the movable cutter |2|.

Because of the concentric relation ofthe arcuate guide slot |3| and the internal gear ||l9,"the

carrier block |34 and associated pinion |42 and cutter unit 98. may be readily adjusted in divers vertical positions with the pinion |42 and internal gear |59 remaining at all times inoperative relation. A tighteningfof the nuts |53 lwill serve effectively to maintain the carrierv block |34 `and cutter unit tion. v

To compensate for the arcuate movement of the carrier block during the above adjustments and thus achieve an absolutely vertical as distinguished from an an'gula-rly vertical support of the cutter unit even though the carrier block is.

moved an appreciable extent in the guide slot, the nut |53 on the bolt passing through the slot |48 in the connecting plate |45 may beloosened and the cutter unit swung to one vside or the other as needed. f

When it is desired to support theI cutter unit in a horizontal position, as shown in Fig. 8, the nuts |63 and the entire cutter unit are withdrawn. The nuts are then replaced and slightly tightened on the bolts. Following this operation the kcarrier block |34 is slid around the arcuate slot |3| until the U-shaped section {4|} of the carrier block |34 assumes a horizontal position to have the cutter l unit |34 :associated therewith.

To `facilitate this association ofthe cutterunit 98 fixed in the desired vertical posithe rim |51 of the ground wheel 95 is formed with t aseparable section '|61 which may be removed to give ready access to the carrierblock. Screws |58 passing through the separable section I 61 and` into the ground `wheel webv .provide a :simpler means for normally maintaining the separable" section in position. Asshown,v a` section |59 4of` the'tre is also made separable in order that the same may be'removed with the section |61 of the rim without removing the whole tire.

with the carrier block |34 land actuating member |35 in the horizontal position, the unit is irst placed in such a way that the roller collar |54 adjacent the link |43 extends into a cam groove |10 formed inthe cylindricalsurface of. the actuating 41o y In operatively connecting the vcutter unit 93 l I rnemberd and substantiallyinythe form ofja Y sine curve,v see Fig. 8. Screws '|1| are then serted in the hole |41 and slot |48 in the connecting plate |45 of the fixed cutter |25 to engage in threaded' holes 412 in the.y U-shaped sectionv |44 of the carrier block |54, see Figs. 9 and 10, to x the cutter unit thereto.l A plate |13,` see especial. -f ly Fig. y10, formed with a slot |14 therein adapted@ V25 to receive the roller collar |54 is then slid over the top 'of the U-shaped section |46) ofthe carrier block |34 to closely confine the lcollar y|515 and-by tain the collar |54 in the cam groove |15.` Screws When the cutter unit 98 carrier block in position, rotation of the ground Tenga-gement with the shoulder |15 thereon mainwheel will through `cooperation ofthe internaly gear |59 and pinion |42` cause the walls of the cylindrical cam groove |10 to Yengage the roller:`

vcollar |54 and thus reciprocate the movable cutter.

ifkit is desired to raise or lower the cutter unit G8 when supported in the horizontal position it t is merely necessary to slide the carrier block |34. upwardly in the arcuate guide slot |3| fromthel lowermost position shownin Fig. 8.

It is thus seen that with the form disclosed in Figs, 5 through 10 as well as with the forms dise closed in Figs. 1 through 4 and Fig. l1 a device tively operate to verticm cut lawn edges and to l 'is provided which not only is adapted to affec horizontal cut the lawn adjacent the lawn edge, A but which also may be. easily converted or` ad-l justed from onetype of operation to the other.v

It is further seen, as in the forms first der scribed, that the, ground wheell 99 provides a housing |11 for enclosing the driving gears of the cutterunit. 1y Variations and modifications `may` bel made within the scope of thisinvention and portions of the improvements` may be used without others. A

Having` thus'described the invention whatfis claimed as new is: y

1. In a lawntrimmer the combinationofa supporting frame; a ground Wheel rotatably mounted on `said frame; a gear on and rotatable with said ground wheel; a pinion meshing fdirectly with'said gear on the ground wheel; a re-f ciprocatingcutter unit supported by the frame 1 and having at least one reciprocating-member;

and a single actuating member secured to andi rotatable with saidpinion, and yconnected di# rectly to saidvcutter unit for reciprocatingthe same and `for member,

supporting `s aicl reciprocating 2. Ina lawn trimmer the combination of a supporting frame; a ground wheel rotatably mounted on said frame; a gear on and rotatable with saidy ground wheel; a pinion meshing rdirectly with said gear on the ground wheel; a reciprocating cutter unit supported by the frame in a vertical position; a single actuating member secured to and rotatable with said pinion, and connected directly to said cutter unit for reciprocating the same; and means for supporting said reciprocating cutter unit at various heights from the ground when in the vertical position.

3. In a lawn trimmer the combination of a supporting frame; a ground wheel rotatably mounted on said frame; a gear on and rotatable `with said ground wheel; a pinion meshing directly with said gear on the ground wheel; an eccentric cam rotatable with and closely adjacent said pinion; a reciprocating cutter unit supported by the frame and comprising at least two blades; and a link connecting said eccentric with at least one of said blades for reciprocating the same.

4. In a. lawn trimmer the combination of a supporting frame; a ground wheel rotatably mounted on said frame; a gear on and rotatable with said ground wheel; a pinion meshing directly with said gear on the ground wheel; a cam enA said pinion; a reciprocating cutter unit supported by the frame and comprising at least two blades; and means connecting said cam with at least one of said blades for reciprocating the same.

5. In a lawn trimmer the combination of a ground wheel having a rim defining an opensded housing; a main frame; a reciprocating cutter supportedin a vertical plane at one side of` the main frame and the ground wheel; a

l gear driving means for saidreciprocating cutter unit entirely within said housing; and means for supporting said reciprocating cutter unit at vari-y ous heights from the ground when in said vertical plane. f

6. In a lawn trimmer the combination of a frame; a ground wheel rotatably mounted on said frame; an arcuate guide on said frame extending parallel with the vertical plane of said wheel; a reciprocating cutter unit; a carrier block for said cutter unit, movable on saidguide to locate the cutter unit in any of a plurality of vertically spaced positions relative to said frame;an actuating member on said block for operating said cutter-unit; ra gear coaxial vwith .said ground wheel and rotatable therewith; and apinion on said 'carrier block and movable therewith to engage said gear in all of said vertically spaced positions to operate said actuating member.

7. Ina lawn trimmerthe combination ofy a frame; `a ground wheel rotatably mounted on said frame; a gear coaxial with said ground wheel and rotatable therewith; a pinion supported by said frame and engageable directly with said gear; a reciprocating cutter unit supported by said frame and extending in a vertical plane at f one side thereof and closely adjacent said wheel; and means secured to and `rotatable with said pinion, and connected directly to said cutter unit for reciprocating .the same.

8. In a lawn trimmer the combination of 4a frame; a ground wheel rotatably supported by said frame and having a peripheral rim; a reciprocating cutter supported by said frame and extending in a vertical plane closely adjacent said wheel; and vmeans within said rimvfor reciprocating said cutter.V

9. In a lawn trimmer the combination of a main frame; a ground wheel rotatably mounted on said frame; a guide on said frame andextending parallel with the vertical plane of 'said wheel; a cutter unit; means for securing said cutter unit to said guide in any of a plurality of vertically spaced positions; a gear coaxial with said ground wheel and rotatable therewith; and a pinion on ,said cutter unit andv engaging said gear in all positions of said cutter unit on said guide. 10. In a lawn trimmer the combination of a 'main frame; a ground wheel rotatably mounted on said frame; a cutter unit; means for securing said cutter unit to said trame in a plurality of vertically'spaced positions; a gear secured to said ground'wheel and rotatable therewith; and only one pinion directly engaging 'said gear and connected directly to said cutter unit in all positions of said cutter unit on said guide.

11. In a lawn trimmer the combination of a mainframe; a ground wheel rotatably mounted on said frame; a cutter unit; means for securing said cutter unit to said frame in a plurality of vertically spaced positions; and only one pair of gears connecting said ground wheel with `said cutter unit `in all positions of said cutter unit for operating the same.

` LESTERy W. SCOFIELD. 

